Facsimile and static presentation processing – Facsimile – Recording apparatus
Patent
1993-02-19
1995-11-28
Reinhart, Mark J.
Facsimile and static presentation processing
Facsimile
Recording apparatus
347256, H04N 121
Patent
active
054713129
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a calibration method essential to a system for the control of an automatic machine, such as a robot, in which an object of operation is detected by means of an external visual sensor, such as an image processing apparatus, and the operating position of the automatic machine is corrected.
BACKGROUND ART
Conventionally known is a system in which an image processing apparatus is utilized as a visual sensor for an automatic machine, such as a robot, so that the deviations of the position and attitude of the object of operation detected by means of the image processing apparatus are detected. The data indicative of these deviations of the position and attitude are delivered as correction data to a control device of the automatic machine; and the control device of the automatic machine performs a specified operation while correcting the operating position in accordance with the correction data. In this case, the operation for the position correction cannot be performed normally unless a coordinate system for an image of the object of operation to be detected by the image processing apparatus and a coordinate system for the operation of the automatic machine are integrated. Accordingly, a process is needed to combine the respective coordinate systems of the image processing apparatus and the control device of the automatic machine.
In order to correct the operation of the automatic machine, such as a robot, in accordance with the correction data indicative of the deviations of the position and attitude of the object of operation detected by the image processing apparatus, it is necessary to transform pixel value data (data in a camera coordinate system) on the image, picked up by a camera of the image processing apparatus, into data in a sensor coordinate system, which is common to the image processing apparatus and the control device of the automatic machine, and also into data in a work coordinate system for the actual drive control of the automatic machine. These coordinate transformations for the data require previous definitions of the respective coordinate axes of the individual coordinate systems. In general, this series of operations is referred to as calibration.
The calibration work comprises operations including:
(1) setting on the visual sensor side and data setting essential to the coordinate definitions;
(2) coordinate definition for the visual sensor;
(3) coordinate definition for the control device of the robot (automatic machine); and
(4) combining the coordinates for the visual sensor and the robot control device.
In executing two-dimensional calibration associated with the image processing apparatus and the robot, for example, the image processing apparatus combines the camera coordinates and sensor coordinates (operations (1) and (2) of the calibration work) by setting the positional relationships between the camera coordinate axis and the sensor coordinates, axis names of the sensor coordinates, pixel size, etc., and then defines the work coordinates for the robot operation (coordinate definition on the robot side described in (3)).
In the aforesaid operation (4), a body which can be recognized by the image processing apparatus, e.g., a jig with a circular object thereon, is first prepared for use and mounted on the robot. Then, the jig on the robot is moved to the origin of the sensor coordinates recognized by the image processing apparatus, and its position (position with respect to the work coordinates for the robot) is stored in the control device of the robot. Then, the robot is moved to specified points on the X and Y axes of the sensor coordinates, and the respective positions of these points are stored individually. Subsequently, these stored data are displayed on a display unit on the robot side, and their respective values are entered in the image processing apparatus. Thereupon, the relationships between the work coordinates for the robot and the sensor coordinates are obtained, and the sensor coordinates recognized by the robot
REFERENCES:
patent: 4581762 (1986-04-01), Lapidus et al.
patent: 5274714 (1993-12-01), Hutcheson et al.
Proceedings of the 1991 IEEE International Conference on Robotics and Automation, Sacramento, Calif., US, 9-11 Apr. 1991, Los Alamitos, Calif., US, pp. 2079-2084, XP221068, B. Preising & T. C. Hsia "Robot Performance Measurement and Calibration Using a 3D Computer Vision System".
International Journal of Robotics Research, vol. 9, No. 4, Aug. 1990, Cambridge Mass., US, pp. 22-39, XP174623, S. B. Skaar, W. H. Brockman & W. S. Jang, "Three-Dimensional Camera Space Manipulation".
Terawaki Fumikazu
Warashina Fumikazu
Watanabe Atsushi
Fanuc Ltd.
Reinhart Mark J.
LandOfFree
Automatic calibration method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Automatic calibration method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic calibration method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2017169